Shirley Mason was the psychiatric patient whose life was portrayed in the 1973 book Sybil. The book and subsequent film caused an enormous spike in reported cases of multiple personality disorder. Mason later admitted she had faked her multiple personalities.

Real 'Sybil' Admits Multiple Personalities Were Fake

Dan Buettner spent years seeking out the happiest populations in the world to try to figure out what characteristics they shared. Tightly knit networks of family and friends were key, he found. In Mexico, for example, Buettner found a "family first" mentality that applied to both immediate and extended family helped Mexicans cope in otherwise stressful circumstances.